Tests conducted by the city, however, show that the E. coli comes from humans, City Manager Tom Luttrell told city councilors during their meeting Monday night.

Where that waste is coming from, however, is still unresolved, though suspicions have now turned to three homes whose sewer lines are hooked up to a storm drain that dumps into the harbor.

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The city had earlier figured out that high levels of E. coli in the waters off the park are the result of sewage coming from the three homes via the storm drain.

Wastewater Plant Director Terry Pinto told the BDN Tuesday that 60 years ago, all sewage went into the harbor. The problem was that when the sewer plant and pump stations were built in the 1970s, it was not known that this storm drain was connected to a sewer line and thus was not connected to the sewer system.

Pinto explained that at high tide E. coli-contaminated water from the harbor could be washing up on shore or seeping up from underground into the park.

Repairs to fix the discharge from the three homes now are nearly complete, Pinto said.

The director said once the repairs are done, the city will wait two to three weeks and test again to see if the problems in the water and on the grounds have been resolved.

In the meantime, Snow Marine Park will remain closed. The city had workers pick up considerable dog wastes and then spread lime on the ground before it tested to determine the species of the E. coli.